Scores of AAP workers stormed the BJP head office on Ashoka Road in the heart of the capital protesting against Kejriwal's detention in Radhanpur in North Gujarat where he has gone on a four-day visit to "inspect" development that has been claimed by Chief Minister Narendra Modi.

They shouted slogans against Modi saying he was "scared" by Kejriwal's visit and was using the police against him.

Soon both sides were engaged in pelting of stones alleging that the other side started it. Police which reached the spot sought to disperse the crowd by using water cannons. Plastic chairs were also hurled from inside the BJP office on the crowds outside.

The scene outside the BJP office looked a veritable battle scene with activists of both sides pelting stones and other missiles at each other. At least five people from either side were injured, police said. An FIR will be filed in the case.

But AAP leaders hit back saying it was the BJP activists who provoked violence.

"We cannot change the path of our caravan. What was the need to detain Kejriwal? Modi is scared of Kejriwal. Rahul Gandhi is in Aurangabad but he wasn't stopped. This rally was fixed days in advance," AAP leader Shazia Ilmi, who was among the protesters, said.

"What was the need to fire water cannons and throw stones at us. I was myself standing here. We were only shouting slogans against Modi," she said.

Ashutosh was also critical of the police action. "We have been protesting peacefully. Congress and BJP are hand in gloves. All are scared of AAP."

As he embarked on his four-day tour to verify Modi's claims of providing water, power, education and healthcare to people of Gujarat, Kejriwal was taken to Radhanpur police station in north Gujarat and allowed to go after half an hour.

AAP's state convenor Sukhdev Patel claimed that Kejriwal was detained but police denied it saying they had only "briefed" Kejriwal on the model code of conduct which came into force with the declaration of poll schedule.